DESCRIPTION: The neuropathology core is a shared resource of the AIDS center and plays an important role in studies investigating the pathology and pathogenesis of human immunodeficiency virus (HIV) infection. The applicant, Dr. Carlos Pardo-Villamizar is a fully trained neurologist and neuropathologist who will direct the core and is responsible for the collection and distribution of tissue as well as diagnostic neuropathology on brain and spinal cord tissues. In addition, this core is responsible for the collection, storage and distribution of tissue collected at autopsy from skin and nerve biopsies. Owing to the large numbers of AIDS patients who receive care at Johns Hopkins, the applicants have obtained autopsies on about 10% of those who died with AIDS in the Baltimore metropolitan area.